Einfluss der Umweltnoxe Ozon auf die Haut

The skin is directly and frequently exposed to a pro-oxidative environment, including ozone and UV-radiation. While ozone in the stratosphere protects against mutagenic UVC-radiation, it is also a major air pollutant in urban areas. With its strong oxidizing potential, ozone is perhaps one of the most reactive chemicals the skin ever encounters. Although a large body of evidence exists for ozone- induced oxidative stress in the respiratory tract, the current knowledge on its in vivo effect on cutaneous tissues is based on studies of the last 10 years. Acute ozone exposure damages the stratum corneum, depletes skin vitamin C and E and induces lipid and protein oxidation in upper epidermal layers. Secondary products penetrate into deeper skin layers and are capable of activating signal transduction pathways and inducing cell damage. It has been shown in a murine model, that environmentally relevant ozone concentrations can induce a stress response in the skin.

Repetition rate increase and diffraction-limited focal spots for a nonthermal-equilibrium 100-TW Nd:glass laser chain by use of adaptive optics

Dynamic wave-front correction is applied before each shot on a 100-TW, 30-J/300-fs high-power laser facility by use of an adaptive-optics system. This system allows us to increase the repetition rate of high-energy lasers while maintaining excellent and constant beam focusability with a Strehl ratio of >0.75 despite the amplifiers' not being in thermal equilibrium. The best results in terms of the highest Strehl ratio and intensities are obtained when locking the system on wave-front sensing after pulse recompression.

ECG-guided central venous catheter positioning: does it detect the pericardial reflection rather than the right atrium?

BACKGROUND AND OBJECTIVE

Although electrocardiography (ECG) guidance of central venous catheters (CVCs) is traditionally thought to detect the entrance into the right atrium (RA), there is little evidence in the literature to confirm this. We previously observed a high incidence of left-sided CVCs abutting the wall of the superior vena cava (SVC), even when the catheters were advanced past the point of increased P-wave amplitude. Our hypothesis was that this ECG amplitude signal is actually detecting the pericardial reflection rather than the RA. The goal of the study was to position catheter tips under ECG guidance outside the RA.

METHODS

One-hundred central venous triple-lumen catheters inserted either via the right or the left internal jugular veins, respectively, were analysed in cardiac surgical patients. The position of the catheter tip was ascertained by ECG. METHOD A: A Seldinger guide-wire in the distal lumen served as exploring electrode, the respective insertion depth was recorded. METHOD B: The middle lumen (port opening 2.5 cm from the catheter tip, thus the catheter was advanced more towards the atrium) filled with a saline 10% fluid column served as the exploring electrode, and the insertion depth was recorded again. Descriptive data are given as mean+/-standard deviation.

RESULTS

On average, the catheters were advanced by the expected 2+/-0.3 cm using Method B beyond the initial insertion by Method A. All 100 CVCs were finally correctly positioned in the SVC and confirmed by transoesophageal echocardiography. When chest radiography was performed after surgery not a single catheter abutted the lateral wall of the SVC.

CONCLUSION

Since both methods detected the same structure, and catheters placed by Method B did not result in intra-atrial CVC tip position, the first increase in P-wave amplitude does correspond to a structure in the SVC, most likely the pericardial reflection.

Ultralow emittance, multi-MeV proton beams from a laser virtual-cathode plasma accelerator

The laminarity of high-current multi-MeV proton beams produced by irradiating thin metallic foils with ultraintense lasers has been measured. For proton energies >10 MeV, the transverse and longitudinal emittance are, respectively, <0.004 mm mrad and <10(-4) eV s, i.e., at least 100-fold and may be as much as 10(4)-fold better than conventional accelerator beams. The fast acceleration being electrostatic from an initially cold surface, only collisions with the accelerating fast electrons appear to limit the beam laminarity. The ion beam source size is measured to be <15 microm (FWHM) for proton energies >10 MeV.

Dauer der unbehandelten Psychose (DUP): Ein brauchbarer Prädiktor für den Krankheitsverlauf?

The concept of DUP has gained much interest as a possible predictor of outcome variables. The review of the current state of research suggests that DUP may be related to remission, social functioning and severity level of symptomatology. In the present retrospective-prospective study 50 first-time admitted patients were interviewed with the "Interview for the Retrospective Assessment of the Onset of Schizophrenia" (IRAOS). Outcome was measured after six months and one year with the "Positive and Negative-Syndrom Scale" (PANSS) and the "Disability Assessment Schedule" (DAS). Patients with long DUP had a worse outcome regarding the severity level of positive symptoms, of general symptoms and social disability. Corresponding well with some other studies, there was no association between DUP and negative symptoms.

CONCLUSION

DUP can be regarded as an useful predictor of outcome in schizophrenia. However, further research is required to confirm these results in long-term studies.

Hypoxia-induced long-term increase of dopamine and tyrosine hydroxylase mRNA levels

The aim of the present study was to determine hypoxia-induced changes in the long-term expression of tyrosine hydroxylase (TH) mRNA and the steady-state dopamine (DA) levels in rat mesencephalic cell cultures. The cultures were exposed to hypoxia during the early developmental period, and DA content and TH mRNA expression were determined on day in vitro (DIV) 14. Hypoxic exposure of 5-day-old cultures resulted in increased DA (control 89.9+/-8.9, hypoxia 135.8+/-23.7 pg/microg protein) and TH mRNA (control 37.3+/-4.7, hypoxia 143.1+/-49.4 pg/microg RNA) levels. To analyze the involvement of hypoxia-inducible factor-1 (HIF-1) in these changes, we studied its activation using reporter gene. Hypoxia caused a 3-fold increase in HIF-1 activity. Our data suggest that hypoxia/ischemia during the putative critical developmental period of neurons may determine the tyrosine hydroxylase gene expression and, consequently, the development of the dopaminergic system.

Observation of ion acoustic waves associated with plasma-induced incoherence of laser beams using Thomson scattering

We have carried out experiments to investigate the physical processes responsible for the recently discovered phenomenon of plasma-induced incoherence (PII) of a laser beam. Using a Thomson scattering diagnostic, we have observed ion acoustic waves (IAW) having wave vectors transverse to the interaction beam spectral and temporal characteristics of which show a clear correlation with other signatures of PII for various conditions of plasma density and laser intensity. These results support the recent theoretical interpretation for which the IAW result from the coupling between forward stimulated Brillouin scattering and self-focusing of the laser light in PII mechanisms.

Spatial uniformity of laser-accelerated ultrahigh-current MeV electron propagation in metals and insulators

The evolution of laser-generated MeV, MA electron beams propagating through conductors and insulators has been studied by comparing measurement and modeling of the distribution of MeV protons that are sheath accelerated by the propagated electrons. We find that electron flow through metals is uniform and can be laser imprinted, whereas propagation through insulators induces spatial disruption of the fast electrons. Agreement is found with material dependent modeling.

Intra-atrial ECG is not a reliable method for positioning left internal jugular vein catheters

BACKGROUND

ECG guidance is widely used for positioning central venous catheters (CVCs) in the superior vena cava. We noticed a higher incidence of a more perpendicular angle between the catheter tip and the vessel wall after left-sided ECG-guided catheter positioning. To investigate the value of left-sided ECG guidance, we performed this prospective study.

METHODS

Of 114 patients, 53 were randomized to right and 61 to left internal jugular vein catheterization using a triple lumen catheter. Three methods to ascertain catheter tip position were sequentially applied in each patient, and the insertion depths (ID) obtained using each of the three methods were recorded: (i). ECG guidance with a Seldinger guide wire (ID-A); (ii). ECG guidance with saline 10% used as an exploring electrode (ID-B); (iii). from position ID-B, the catheter was rotated and advanced until all three lumina could be aspirated easily. The catheter was fixed in that position (ID-C). To determine final catheter tip position, intraoperative transoesophageal echocardiography (TOE) and a postoperative chest X-ray (CXR) were performed.

RESULTS

The depth of insertion of a catheter using the three methods varied significantly in left-sided (P<0.001), but not in right-sided catheters. Forty-eight of 57 (84%) left-sided CVCs, correctly positioned according to ECG guidance, had to be advanced further to achieve free aspiration through all three lumina. By this stage, five of the catheter tips had been positioned in the upper right atrium as demonstrated by TOE. There were 13 malpositions (23%) after left-sided insertion. In nine catheter malpositions, undetected by ECG guidance, the angle between the catheter tip and the lateral wall of the superior vena cava exceeded 40 degrees on CXR.

CONCLUSIONS

Intra-atrial ECG does not detect the junction between the superior vena cava and right atrium. It is not a reliable method for confirming position of left-sided CVCs. Post-procedural CXRs are recommended for left-sided, but not right-sided CVCs.

Interventional treatment of infantile hepatic hemangioendothelioma

BACKGROUND/PURPOSE

Hemangioendothelioma is the most frequent liver tumor in infancy. Untreated symptomatic patients with heart failure have a high mortality rate. Symptomatic forms may request nonoperative treatment, because surgery is burdened with high risks in patients with heart failure. The authors report their experience with interventional coil occlusion of infantile hepatic hemangioendothelioma (IHE).

METHODS

Four patients (age range, 2 to 146 days; mean, 53 days) suffering from IHE associated with heart failure were treated by endovascular coil occlusion of arterial feeders. Catheter intervention was performed via an arterial (n = 2) or venous (n = 2) approach.

RESULTS

Signs of heart failure resolved within 2 to 8 days after occlusion in 3 patients. Tumor regression could be observed sonographically within 4 weeks postinterventionally. In 3 children, tumor size was reduced from a mean of 544 mL (65 to 1,350) to a mean of 4 mL (2 to 6); Mean systolic peak velocity in the hepatic artery was decreased from 170 cm/s (140 to 200) before occlusion to 45 cm/s (36 to 70) during follow-up. In the fourth patient, endovascular intervention could not control a rapidly progressing hemangioendotheliomatosis, and finally a liver transplantation had to be performed.

CONCLUSIONS

Interventional occlusion of feeding arteries in symptomatic IHE is a safe and effective alternative to early open surgery. The efficacy of endovascular intervention in multifocal tumors seems questionable.

UV-induced free radicals in the skin detected by ESR spectroscopy and imaging using nitroxides

Reactive free radicals and reactive oxygen species (ROS) induced by ultraviolet irradiation in human skin are strongly involved in the occurrence of skin damages like aging and cancer. In the present work an ex vivo method for the detection of free radicals/ROS in human skin biopsies during UV irradiation is presented. This method is based on the Electron Spin Resonance (ESR) spectroscopy and imaging and uses the radical trapping properties of nitroxides. The nitroxides 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO), 3-Carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (PCM), and 3-Carboxy-2,2,5,5-tetramethylpyrrolidine-1-oxyl (PCA), were investigated for their applicability of trapping reactive free radicals and reactive oxygen species in skin during UV irradiation. As a result of the trapping process the nitroxides were reduced to the EPR silent hydroxylamins. The reduction rate of TEMPO was due to both the UV radiation and the enzymatic activity of the skin. The nitroxides PCM and PCA are sufficiently stable in the skin and are solely reduced by UV-generated free radicals/ROS. The nitroxide PCA was used for imaging the spatial distribution of UV-generated free radicals/ROS. As a result of the homogeneous distribution of PCA in the skin, it was possible to estimate the penetration of UVA and UVB irradiation: The UV irradiation decreased the PCA intensity corresponding to its irradiance and penetration into the skin. This reduction was shown to be caused mainly by UVA radiation (320-400 nm).

Multibeam stimulated brillouin scattering from hot, solid-target plasmas

We report on multibeam, laser-plasma interaction experiments in plasmas relevant to future direct-drive-ignition experiments. Six interaction beams are incident on preformed plasmas containing critical density. Stimulated Brillouin scattering (SBS) shows strong evidence of electromagnetic wave seeding of side- and backscattering. The data are also consistent with shared ion waves driven by the six symmetrically arranged interaction beams. Early SBS quenching is observed and attributed to the hydrodynamics of the plasma.

Impact of magnetic resonance urography on preoperative diagnostic workup in children affected by hydronephrosis: should IVU be replaced?

PURPOSE

The aim of this study was to determine the role of magnetic resonance urography (MRU) in preoperative diagnostic workup of children with hydronephrosis in a prospective clinical study with comparison of MRU, standard diagnostic investigations, and intraoperative findings.

METHODS

Thirty-one children with hydronephrosis secondary to different causes underwent ultrasound scan (US), intravenous urography (IVU), micturation cysto-urethrography (MCU), isotope nephrography (ING) and MRU. For MRU the authors performed sagittal and coronal halve-Fourier SSFSE scans in a 1.5 Tesla MR system. T1- and T2-weighted sequences were used in axial orientation to improve morphologic information. In 24 patients, preoperative data were compared with intraoperative findings.

RESULTS

Comparison of the different imaging modalities proved MRU to be able to provide more detailed information about the correct localization of stenoses along the urinary tract and the morphology of renal parenchyma. MRU showed the highest concordance of all imaging modalities with intraoperative findings.

CONCLUSION

As a reliable investigation, MRU has the potentials to replace IVU in preoperative diagnostic workup of hydronephrosis in childhood.

Electron spin resonance detection of UVA-induced free radicals

Free radicals generated during UV irradiation of human skin biopsies were measured with electron spin resonance spectroscopy by using spin traps. The generation of hydroxyl and lipid radicals in skin is mainly caused by the UVA part of the solar spectrum.

MeV ion jets from short-pulse-laser interaction with thin foils

Collimated jets of carbon and fluorine ions up to 5 MeV/nucleon ( approximately 100 MeV) are observed from the rear surface of thin foils irradiated with laser intensities of up to 5 x 10 (19)W/cm(2). The normally dominant proton acceleration could be surpressed by removing the hydrocarbon contaminants by resistive heating. This inhibits screening effects and permits effective energy transfer and acceleration of other ion species. The acceleration dynamics and the spatiotemporal distributions of the accelerating E fields at the rear surface of the target are inferred from the detailed spectra.

The influence of preoperative chemotherapy and surgical technique in the treatment of hepatoblastoma--a report from the German Cooperative Liver Tumour Studies HB 89 and HB 94

Despite the success of chemotherapy in the treatment of hepatoblastoma (HB), the complete surgical resection of the primary liver tumour and metastases is the most important factor for survival.

METHODS

From 1989 to 1998, 141 children with HB were treated in the German Cooperative Paediatric Liver Tumour Study HB 89 and HB 94. The study determines the results of surgical strategy, which adapts the procedure at the initial operation to the tumour extension in the liver and the occurrence of metastases.

RESULTS

The median follow-up of the survivors was 72 months (range 24 - 132 months). 98/141 (78 %) patients were alive and 31/141 (22 %) died. 12/141 (8.5 %) children had no surgical treatment. A complete resection of the primary tumour was achieved in 107/129 (83 %) cases. Forty-eight children were primary resected and eighty-one children were operated on after initial chemotherapy. In 36 cases, an atypical tumour resection, in 90 cases an anatomical liver resection, was performed. Three children were transplanted. There was no perioperative death. 14/48 (30 %) children with primary tumour resection had microscopical or macroscopical residual tumour in the liver. Despite the larger number of advanced HB in the primary chemotherapy group, an incomplete tumour resection was performed in only 15/78 (19 %) cases after liver resection (p < 0.044). 14/36 (38 %) cases with atypical tumour resection and only 16/90 (18 %) cases with anatomical liver resection had residual tumours in the liver (p < 0.019). These results underline the necessity for preoperative chemotherapy in all HB, which was accepted in the following study HB 99. Atypical tumour resection should be avoided because of the higher rate of incomplete tumour resections and local relapse compared to the group with anatomical tumour resection.

Langmuir decay instability cascade in laser-plasma experiments

Thomson scattering has been used to investigate the nonlinear evolution of electron plasma waves (EPWs) generated by stimulated Raman scattering (SRS). Two complementary diagnostics demonstrate the occurrence of the cascade of Langmuir decay instabilities (LDI). The EPW wave-number spectrum displays an asymmetric broadening towards small wave numbers, interpreted as a signature of the secondary EPWs produced in the LDI cascade. The number of cascade steps is in agreement with the broadening of the associated ion-acoustic-waves' spectra. The total energy transferred in the EPWs cascade is found to be either less than or of the same order of magnitude as the energy of the primary EPW.

Reduction of the coherence time of an intense laser pulse propagating through a plasma

We present direct measurements of the coherence time of a laser beam after propagation through an underdense plasma. At an intensity of 10(14) W/cm(2), a large decrease of the coherence time is observed, from 300 ps to a few picoseconds. This decrease is larger as the plasma density is increased or as the light is scattered at larger angles. The amount of temporal decorrelation as well as the effect of the plasma density, laser intensity, and scattering angle all coincide with trends observed in recent numerical simulations.

[Gender-sensitive public health publications in Germany? Results of a review of literature]

BACKGROUND

The project 'Gender Bias - Gender Research' investigates how far gender issues are considered in German-language Public Health journals. Target is the analysis of the publication practice in Public Health in order to point out status, deficits and perspectives of gender-specific research.

METHODS

We developed a standardised evaluation instrument, which covers the semantic, methodical-technical and contentual area regarding gender issues and evaluated all original contributions of the years 1990, 1995 and 1999 in the journals 'Das Gesundheitswesen', 'Sozial- und Präventivmedizin' and 'Zeitschrift für Gesundheitswissenschaften'. 268 (of 517) contributions applied to persons (in contrast to i. e. programmes, institutions) and were completely analysed.

RESULTS

The main part of the contributions take women and men into account, but do not consider them continuously in all parts of the research process and in this way do not fulfil all requirements for gender-sensitive research. Gender finds most consideration on the semantic level. Less than half of the authors consider the different situation of women and men in the formulation in hypotheses, sampling, or data analysis, and only 35 % of them make reference to this in their conclusions. We found differences between the examined journals and years.

CONCLUSIONS

The concerns of women and men should be considered at all levels of research. Attention should be paid to this when writing, reviewing and publishing contributions.

Cystic echinococcosis with perforation into the biliary tract in an eight-year-old girl

Cystic echinococcosis (CE) is a zoonotic infection caused by echinococcus granulosus and is still frequent in endemic areas. CE is predominantly localised in the liver. The therapy of choice is the surgical sanitation of the lesions, increasingly through interventional procedures such as percutaneous punctation of the cysts, aspiration of the cystic fluid, instillation of a protoscolicidal solution and reaspiration of this solution (PAIR). However, in some cases, such as perforation into the biliary tract, PAIR is not feasible. We report on an eight-year-old girl who suffered from CE with perforation of one cyst into the biliary tract. The diagnosis was confirmed by ERCP and cholangioscopy and a right hemihepatectomy was performed. The girl received adjuvant chemotherapy with albendazol perioperatively and is still asymptomatic with no indications of disease 10 months after the operation.

[Pathways to psychiatric care and duration of untreated psychosis in first-episode psychosis patients]

To reduce the time of untreated psychosis it is necessary to know the patients' pathways to psychiatric care. For this reason we interviewed 50 first-episode patients with the Interview for the Retrospective Assessment of the Onset of Schizophrenia (IRAOS) for information about duration of untreated psychosis (DUP) and about their help-seeking contacts before psychiatric admission. In contrast to other findings of long DUP, 50 % of our patients were admitted after 8 weeks (median) of untreated positive symptoms. The mean value of 62 weeks corresponds well with results of other studies. There were important differences in DUP depending on which kind of statistical parameter (median or mean) was used. Contrary to studies from other countries only 24 % of our patients had their first contact with a general practitioner. Between patients with short (< 1 year) and long (> 1 year) DUP no significant differences were found in contacts with helpers and in the duration from the first contact until psychiatric admission. However, patients with long DUP made their first contact with helpers significantly later after the beginning of positive symptoms than patients with short DUP.

[Infantile hemangioendothelioma of the liver--sonographic diagnosis and follow-up]

OBJECTIVE

Hepatic haemangioendothelioma is the most frequently observed hepatic tumour of early infancy. Lesions may cause life-threatening disease due to av-shunt-related cardiac failure, Kasabach-Merritt syndrome or encroachment on surrounding tissue. In this paper, the value of ultrasonography at initial work-up as well as during follow-up under various management strategies is discussed.

METHOD

Retrospective analysis of sonographic and clinical data as well as outcome of 14 patients.

RESULTS

The tumours may present initially with a typical sonographic pattern of a roundish solitary lesion consisting predominantly of massively perfused, tortuous cavities. In these cases, histological verification of the diagnosis is not mandatory, provided serological tumour markers are negative. Multifocal haemangioendotheliomata with a solid appearance, however, cannot be reliably distinguished from other entities sonographically. Tumour development - with or without therapy - can be followed up precisely using repeated ultrasound evaluations of tumour volume and sono-morphology as well as Doppler examination of tumour perfusion.

CONCLUSIONS

Guidelines for the management of these patients are discussed, based on our experience and a review of the literature. Sonography proves to be of outstanding importance.